One ring to rule them all: From cell polarity to bacterial virulence control
Urs Jenal, Professor of Molecular Microbiology
Biozentrum, University of Basel
Bacteria are masters in adapting to different environments by gradually adjusting their physiology and resilience or by functionally diversifying through cell differentiation processes. Distinct behavioural programs either result from cell polarity and asymmetric divisions or arise from binary decisions that give rise to functionally heterogenous populations. In this lecture, I will discuss how bacterial cell fate programs are determined by the small signalling molecule c-di-GMP, a member of a growing family of highly versatile nucleotide-based signalling molecules that control important biological processes in bacteria and eukaryotes. I will present examples illustrating how c-di-GMP controls growth and behaviour of environmental and pathogenic bacteria. In particular, I will explain how c-di-GMP oscillations determine cell fate and behaviour of Caulobacter crescentus, an aqueous bacterium with a characteristic bi-modal life cycle. I will explain how work in this non-pathogenic model organism has provided a conceptual frame for studies in the human pathogen Pseudomonas aeruginosa and I will provide an update on how P. aeruginosa makes use of c-di-GMP to effectively colonize surfaces and disseminate in the host. Finally, I will present an example for how bacteria generate stochastic distributions of c-di-GMP and how such processes can generate population heterogeneity and memory effects during developmental transitions.
